I have just recently upgraded my CPU to the E8400 from an old dual core 6600. I have an Asus P5B Deluxe motherboard, 4GB of Corsair CMX1024 6400 400mhz Ram an 8800GTX Nvidia + 4 Hard drives. I have been used to doing simple overclocking following the guides and i was able to achieve 3.0Ghz on air on my last chip... Now i read that these E8400 were good at overclocking up to 4.0Ghz so I installed it and am able to via the bios run the FSB at 445Mhz (chip voltage at 1.36) and it runs Orthos without any problems... However if I try to play Crysis or Microsoft Flight Simulator that frame rate drops dramatically and becomes very choppy. I decided to download Aquamak3 and found a very strange situation if I overclock up to 3.3Ghz FSB 370.0 I get this result on Aquamark3 GFX 37,425 CPU 19,565 when I increased it to 3.6GHZ suddenly the GFX score drops while the CPU score increases as it should basically it reads GFX 6,405, CPU 20,794 this would explain why my games are running so stuttery... does anyone know why the graphics score drops so suddenly after 3.4Ghz overclock? I am running a 650Watt PSU...

Thanks Guys for replying so quickly... I have filled out my computer specs in the edit CP tab. I have a 500W Seasonic PSU and my memory is 4 X 1GB Corsair CM2X1024-6400 DDR2 400 and the timings are 5.0-5-5-18... maybe it is a power issue as I am also running 4 hard disc drives and I have 3 17"monitors running of a Matrox Triple Head2go box which is powered by USB... If it was a power issue does it make that much of a difference from running well at 3.3Ghz overclock and terribly at 3.4Ghz as far as the graphics card is concerned?

I have just recently upgraded my CPU to the E8400 from an old dual core 6600. I have an Asus P5B Deluxe motherboard, 4GB of Corsair CMX1024 6400 400mhz Ram an 8800GTX Nvidia + 4 Hard drives. I have been used to doing simple overclocking following the guides and i was able to achieve 3.0Ghz on air on my last chip... Now i read that these E8400 were good at overclocking up to 4.0Ghz so I installed it and am able to via the bios run the FSB at 445Mhz (chip voltage at 1.36) and it runs Orthos without any problems... However if I try to play Crysis or Microsoft Flight Simulator that frame rate drops dramatically and becomes very choppy. I decided to download Aquamak3 and found a very strange situation if I overclock up to 3.3Ghz FSB 370.0 I get this result on Aquamark3 GFX 37,425 CPU 19,565 when I increased it to 3.6GHZ suddenly the GFX score drops while the CPU score increases as it should basically it reads GFX 6,405, CPU 20,794 this would explain why my games are running so stuttery... does anyone know why the graphics score drops so suddenly after 3.4Ghz overclock? I am running a 650Watt PSU...

Any help most appreciated...

Hamish

Open up GPU-z and tell us what the Link width says, bet you its at x1 instead of x16

I am not sure it could be a bad chip as it runs Orthos for an hour at 4.0Ghz without any errors it just seems to affect the graphics card. I will do some testing to see the absolute maximum I can raise the FSB unitl the graphics are affected... I am using Aquamark3 to do the testing......